From ochoi@purdue.edu Tue Apr 26 02:31:12 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!ochoi From: ochoi@purdue.edu (Olga Choi) Newsgroups: comp.sys.m68k Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Apr26.023112.2103@purdue.edu> Date: Tue, 26 Apr 1994 02:31:12 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Olga Choi Opinions expressed are solely my own and not those of Purdue University Engineering Computer Network. ------------------------------------------------------------ From tmoreno@purdue.edu Wed Apr 27 01:11:12 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!purdue!tmoreno From: tmoreno@purdue.edu (Tobias Moreno) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Apr27.011112.1518@purdue.edu> Date: Wed, 27 Apr 1994 01:11:12 GMT References: <1994Apr26.023112.2103@purdue.edu> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1994Apr26.023112.2103@purdue.edu>, ochoi@purdue.edu (Olga Choi) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Tobias Moreno Tape trading list upon request. SASE required for international mail. From efournier@cmu.edu Thu Apr 28 18:46:12 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!cmu!efournier From: efournier@cmu.edu (Emi Fournier) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Apr28.184612.1057@cmu.edu> Date: Thu, 28 Apr 1994 18:46:12 GMT References: <1994Apr26.023112.2103@purdue.edu> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1994Apr26.023112.2103@purdue.edu>, ochoi@purdue.edu (Olga Choi) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Emi Fournier "Row 14. No joke." 486DX4/100 (FreeBSD 2.0.5) / FreeBSD 2.1 From ktanaka@rwth-aachen.de Fri Apr 29 10:37:12 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!rwth-aachen!ktanaka From: ktanaka@rwth-aachen.de (Karen Tanaka) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Apr29.103712.9606@rwth-aachen.de> Date: Fri, 29 Apr 1994 10:37:12 GMT References: <1994Apr26.023112.2103@purdue.edu> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Apr26.023112.2103@purdue.edu>, ochoi@purdue.edu (Olga Choi) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Karen Tanaka Tape trading list upon request. SASE required for international mail.